These directories are called process directories, as they are named after a program's process ID and contain information specific to that process. The owner and group of each process directory is set to the user running the process. When the process is terminated, its /proc/ process directory vanishes.

Each process directory contains the following files:

cmdline — Contains the command issued when starting the process.

cwd — A symbolic link to the current working directory for the process.

environ — A list of the environment variables for the process. The environment variable is given in all upper-case characters, and the value is in lower-case characters.

exe — A symbolic link to the executable of this process.

fd — A directory containing all of the file descriptors for a particular process. These are given in numbered links:

maps — A list of memory maps to the various executables and library files associated with this process. This file can be rather long, depending upon the complexity of the process, but sample output from the sshd process begins like the following:

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